High sensitive electrochemical sensor for sunset yellow detection in drink based on Co4(PW9O34)2@PPy-MWCNTs nanocomposite

Sunset yellow(SY) is a synthetic azo food dye, which is extensively utilized in the food processing industry. Nevertheless, its potential detrimental impacts on human health necessitate meticulous consideration. Consequently, the development of a user-friendly and rapidly responsive assay for the monitoring and analysis of SY in food products is of utmost importance. This study introduces an innovative electrochemical sensor based on polyoxometalates decorated with polypyrrole and multi-walled carbon nanotubes [Co 4 (PW 9 O 34 ) 2 @PPy-MWCNTs] for SY detection. The Co 4 (PW 9 O 34 ) 2 composite was prepared by using the nitrogen-containing ligand (1,4-bis (1-imidazolyl) butane) and the conductive polypyrrole was coated on Co 4 (PW 9 O 34 ) 2 , which avoided the solution of polyoxometalates in the electrolyte and improved the electrochemical stability. Multi-walled carbon nanotubes was employed to further enhance electron transfer rate. Research has shown that Co 4 (PW 9 O 34 ) 2 @PPy-MWCNTs exhibits superior electron transfer rates and remarkable electrocatalytic activity, which significantly amplify the oxidation signal of SY. Under optimal experimental conditions, the established detection range for SY is 10–1150 μM, with a detection limit of 0.425 μM. Additionally, the Co 4 (PW 9 O 34 ) 2 @PPy-MWCNTs modified electrode has good anti-interference and stability. The Co 4 (PW 9 O 34 ) 2 @PPy-MWCNTs modified electrode was successfully applied to detect SY in Fanta with yielding recovery rates between 97.79 % and 101.48 %, demonstrating substantial application potential as an effective means for SY detection.